Jarasandha was preparing to attack Mathura 18th time. Krishna
learnt that the army of Jarasandha this time will be led by Kalayavan. As per destiny, this
commander was destined to destroy Mathura.

Krishna who realized this asked all the people of Mathura to follow Him. From Mathura, Krishna and his followers moved towards west and made their kingdom in Dwarka – an island. As Dwarka was protected by sea on
all sides, Jarasandha could no longer attack the kingdom.